1. Field of the Invention
The present disclosure relates to a post-production technology for producing stereoscopic contents, and more particularly, an apparatus and a method for depth manipulation of a stereoscopic image enabling a user to manipulate the depth of the stereoscopic image easily and intuitively.
2. Description of the Related Art
Stereoscopic 3D (S3D) in which the depth is perceived from two left and right images was first discovered by a Greek mathematician, Euclid B.C. 300. Euclid described that a person perceives depth based on mutually-different sight information of the right eye and the left eye. Thereafter, an Italian mathematician of 15 century, Leonardo da Vinci names such a sight perception process of a person as stereopsis and tried to represent a stereoscopic sense on a flat canvas. In 1838, Sir Charles Wheastone devised a stereoscopic mirror allowing two pictures to be seen on mirrors of mutually-different angles, and this is known as the origination of a stereoscopic image.
As above, the most distinctive feature of a stereoscopic image is that two images to be seen by both left and right eyes are necessary. From the viewpoint of the production of a stereoscopic content, this means that double resultant images are required to be produced from an initial scenario operation to photographing or CG rendering and a final synthesis operation (in an actual production, double or more budget and efforts are known to be required). In addition, in technologies and know-how necessary for the production of stereoscopic content, techniques that are of a higher level and more delicate than those required for the production of a general content in which one image is produced are necessary. The reason for this is that, in a case where stereoscopic images of two left and right images are erroneously produced, and there is an error to some degree that cannot be perceived by a person, dizziness or pain in the eyes may be caused.
First, a scenario production for left and right images needs to be designed from a pre-production operation. Second, in a production operation, when images are to be photographed, two cameras need to be arranged so as to photograph left and right images, and additional devices and staffs for the operation are necessary. On the other hand, when a stereoscopic CG content is produced without photographing images, two virtual CG cameras are arranged, and the CG contents are respectively rendered, whereby a double rendering time is necessary. Third, in a post-protection operation, operations such as a correction for a stereoscopic image error due to the limit of the production operation and re-adjustment of the depth are further required. Alternatively, many staffs and much efforts are necessary for generating depth information used for generating a stereoscopic content based on a content that has been already produced as a one-eye 2D image (or a single image) in advance and converting the content into two images.
Particularly, a field focused in this disclosure relates to a post-production operation used for adjusting depth. While various methods of adjusting depth are proposed recently, there are disadvantages that conventional methods of adjusting depth, generally, require user's professional knowledge and are mainly performed in a rendering process to which several restrictions for a stereoscopic content are applied. In other words, a method of adjusting depth of a stereoscopic image that enables a user to adjust depth of a stereoscopic image simply and intuitively has not been proposed yet.